Upon leaving the capital and traveling 10 miles, you come to a river named Puli Sangan,

which discharges itself into the ocean and is navigated by many vessels entering from thence

with considerable quantities of merchandise. Over this river, there is a very handsome bridge of stone,

perhaps unequaled by another in the world. It has 24 arches, supported by 25 piers erected in the water,

all of serpentine stone, and built with great skill.

Marco Polo, Book of the Marbles of the World, published circa 1300.

Welcome to the history of the 20th century. Episode 301, the Marco Polo Bridge.

In last week's episode, we got caught up on major developments in China and Japan in the years following

Japan's occupation of Manchuria. In China, Chiang Kai Shik abandoned Manchuria to Japan without a fight

and agreed to Japanese demands that China demilitarize a swath of Chinese territory along the border

with Manchuria,

so that he could concentrate on reigning in the warlords and especially the communists,

much to the dismay and outrage of Chinese nationalists.

Then in 1936, Chang was kidnapped by two unhappy military commanders who had cut a deal with the communists.

Chang was released in exchange for a promise that the Republic of China would end its military campaigns against the communists

and instead ally with the communists to resist the Japanese.

Soon after, communist military units were integrated into the National Army.

This cooperation agreement is known to history as the second United Front.

The first United Front was the 1924 alliance

between the Nationalists and the Communist,

put an end to the warlords,

which ended in 1927 when Chang abruptly purged the communists

...